Fire-extinguishing composition



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STATES- rnnnnnrcxt. DUNLAI', or CHICAGO, ILLINOIS,

PATENT, OFFICE.

AND NATHANIEL r. Ewan, or

SWAB'IHMOBE, PENNSYLVANIA, ASSIGNORS TO AMDYCO CORPORATION, OF NEW YORK, N. Y., A' CORPORATION OF NEW YORK.

FIBE-ExTmG-UISHING COMPOSITION.

' No Drawing.

This inventionrelates to fire-extinguishing compositions, and particularly to compositions including the ingredients necesproduce a stable and tenacious foam sary to when the composition is combined with water.

The use of foam for fire-extinguishing purposes, especially for oil tires, is well known. The commercial systems heretofore in use have depended upon the storage of solutions containing respectively materials such as sodium bicarbonate and aluminum sulphate, one of the solutions having in addition a stabilizing ingredient such as an extract of licorice or of oak bark or some other material intended to increase the surface tension of the water films which surround the gas bubbles in the foam. Such systems have the defect that the supply of foam depends upon the capacity of the tanks which are expensive to install and maintain. Thesolutions are, moreover, subject to deterioration in storage. v

Compositions including all of the necessary ingredients to produce foam'when the composition is combined with water have also been suggested, and a method-of producing foam continuously from such comositionsis described in the application of alter Palmer, Serial No. 23,266. The composition may. consist, for example, of sodium bicarbonate, aluminum sulphate and a suitable stabilizer as above described ina dry and relatively finely divided condition. Such a composition can be fed to a stream of water and upon contact therewith will produce a satisfactory foam.

The valueof any fire-extinguishin medium depends npon its availability w en a fire occurs and often the medium remains in storage for long periods when it is not needed. We have investigated dry fire-extinguishing compositions containing, materials such as sodium bicarbonate and aluminum sulphate with a stabilizing ingredient and have found that they are subject sometimes to decomposition in storage and'thatthey are not, therefore, entirely reliable;

y The aluminum sulphate of commerce often has the formula A1,(SO,) .18H O, that is to say, it carries eighteen mo ecules of water of crystallization. Another com-' mercial form .nf aluminum sulphate contains fourteen moleculesof water ofcrystal- Application filed April 21,1926. Serial No. 103,631.

of uncombined water which is capable of initiating a reaction between aluminum sulphate and A sodium bicarbonate. If (water of crystallization is present in the aluminum sulphate more freewater is liberated by the reaction which is thereby propagated progressively throughout the mass. The possibility of such a reaction could be avoided by substantially complete dehydration, that is. the removal of free and combined water from the materials of the composition and particularly from the aluminum sulphate; A new difiiculty is introduced, however, because the anhydrous salt is not sufliciently soluble to react with the required speed when the composition is added to a flowing stream of water.

It is the, object of the invention to provide compositions for fire-extinguishing use in which the several factors affecting the speed of reaction and the keeping quality of t e product are so correlated as to produce the most eflicient agent.

Other objects and advantages of the invention will be apparent as it is better understood by referenceto the following speciare described.

We. have discovered that the speed of re action between the ingredients of the composition when it is mingled with water can be accelerated materially by reducing .the sizes of the particles of which it is com posed. The aluminum sulphate used heretofore in such compositions contains a large proportion of particles which will not pass a forty mesh sieve. Such particles dissolve slowly and are, therefore, ineffective. By

reducing the sizes of the particles or by eliminating those which do not pass a forty fication in which the preferred embodiments this material if the particle sizes in the com-' position are below forty mesh.

We have also discovered that the tendency of the ingredients of the composition to react prematurely can be overcome by-the addition of an inert material to the composition. The function of this inert material is to separate the particles of the ingredients which can react. The addition of inert material reduces the gas-forming capacity ,of the composition per unit of weight thereof and consequently lowers the efficiency of the material- If, however, a portion of the water of crystallization is removed from the aluminum sulphate a smaller proportion thereof by weight is required to complete the reaction with the sodium bicarbonate. In this case the inert material is substituted for the water of crystallization and the total gas-forming capacity of the composition can be maintained because the reacting. ingredients constitute substantially the same proportion of the total weight of the composition. The eifect of the removal of water of crystallization upon the speed of the reaction can be overcome as'hereinbefore in.- dicated by reducing the particle'sizes so that the particles will pass a forty meslr sieve.

We can, therefore, by suitably proportioning the amount of water of crystallization and the particle sizes, produce a composition containing froni approximately 8 or 9% to 32 to 35% of inert material by weight. Such compositions are stable and do not deteriorate in storage because of the protection afiorded by the inert material and'by the reduced water content vor both. The compositions are, however, sufliciently re active to produce foam rapidly and efliciently when water is mingled therewith.

The composition may contain aluminumsulphate with fourteen molecules of water of crystallization if inert material is added in suitable proportion. We find it'desirable, however, as hereinbefore indicated, to reduce the water content of the aluminum sulphate and water of crystallization may be removed until the aluminum sulphate containsnot more than seven molecules thereof. This material is sufliciently soluble for the purpose of the invention if the particle size is elow forty mesh.

. We prefer, therefore, to prepare compositions containing the necessary. ingredients with as little Water of crystallization as is practicable in view of the necessity forrapid solution and to accelerate the solution of the materials by reducing the size of the particles. We also prefer to add to the composition as large a proportion of inert material as is possible to protect the material from spontaneous decompositi fpn.

, As the active reacting ingredients of the composition, we prefer to employ aluminum sulphate and sodium bicarbonate.

These materials are readily obtainable in v commerce and they can be obtained in suitable condition or can be reduced readily to that condition. ,The aluminum sulphate may, as hereinbefore indicated, contain fourteen molecules of water of crystallization, but it is preferable to remove some of this water of crystallization down to approximately seven molecules. A further repass a forty mesh sieve Y solved and consequently .the reaction will be correspondingly accelerated when the material is added to water for the purpose of producing foam.

; As a stabilizing ingredient we may utilize extractoflicorice, or extract of oakbark as described in the patent to Ewer, No.

1,527,509, or any other material which can be added for" the purpose of increasing the tenacity of the foam. The usual extracts can be concentratedSby evaporation to roduce a d ry material, which, dition, can be added to reacting ingredients. The size of the particles of the stabilizing ingredient should not be greater than the particle size of the other ingredients of the. composition.

As an inert filler products such as starch or flour, or materials such as china clay or talc. A variety of ifie'rtmaterials having the eral characteristics of the materials tioned are available.

tory form and it can be mixed with the other ingredients of the composition.

- As examples of compositions embodying the invention the following may be considalthough the first c0mp0-.. sition is less stable than the others because ered satisfactory of the relativelylimited amount of inert material and the relatively high proportion of water of crystallization which it contains.

It can be improved by reducing the'water coptent of the aluminum sulphate and by lncreasing the amount of inert material.

ram by in finely divi ed conand mixed with the ion we may employ organic inor anic arge men- We prefer clay because it is readily procurable in a-satisfac- [readily dried and fore identified in which the composition is The following example indicates the preferred composition:

. Parts by weight.

Aluminum sulphate (7 molecules of water of crystallization) Sodium bicarbonate 39. Stabilizer 6 China clay 30 The several ingredients of the composi-- tion set forth are reduced to the proper particle size, that is to say, all particles which do not pass a forty mesh sieve are rejected and the ingredients are then thoroughly mingled until the composition is substantially uniform. The product should thenbe packed in sealedcontainers from. which the moisture of the atmosphere is excluded. When so preserved the compositions will remain substantially indefinitely in their orig- .inal condition. The compositions may be utilized at any time by adding them in proper proportion to water and especially by applying them in accordance with the method of the Palmer application hereinbedrawn'intothe' stream of water by the effect of suction applied at the point of entrance of the powdered material to the stream. When the compositions are thus mixed with water the reaction between the ingredients produces foam immediately. The pressure caused by the gas developed during the reaction is suflicient to eject the foam from the apparatusiin which it is produced. A suitable hose or other connection may be em played to direct the foam upon the surface to be protected. r

It is to be understood that the examples of the compositions as herein set forth are illustrative merely and that the invention is not restricted thereto. Other combinations including changes in the materials andvariations of the proportions may afiord the advantages of "the invention. Various changes may be made, therefore, within the scope of the accompanying claims without departing from the invention or sacrificing the advantages thereof.

We claim 1. A fire-extinguishing composition co m prising ingredients capable of reacting in the presence of water to produce foam, a

foam stabilizer and inert material to avoid deterioration of the composition in storage.

2. A fire-extinguishing composition comprising ingredients capable of reactingin' the presence of water to produce foam, a foam stabilizer and inert'material to avoid deterioration of the composition in storage, the size of the particles of the reacting in-' gredients being such as to accelerate the reaction.

3. .A fire-extinguishing-composition comprising ingredients capable of reacting in prising aluminum sulphate containing no; 6

the presence of water to produce foam, a

the presence of water to produce foam, a

foam stabilizer and from 8 tof35% of an inert material to avoid deterioration of the composition in storage, the sizes of the particles of the reacting ingredients being such as to pass a forty mesh sieve.

6. A fire-extinguishing composition comprising ingredients capable of reacting in the presence of water to produce foam, one of theingredients including water of crystallization, a stabilizing agent and an'amount of inert material suflicient to retard the tendency for the water of crystallization to cause a spontaneous reaction between the ingredi ents.

7 A fire-extinguishing composition comprising ingredients capable of reacting in the presence of water to produce foam, one

of the ingredients including water of crystallization, a stabilizing agent and an amount of inert material sufficient to retard the tendency for the water of crystallization to ;cause a spontaneous reaction between the ingredients, the amount of water of crys tallization' being reduced suificiently to permit the addition ofthe necessary proportion of inert material.

S. A fire-extinguishing composition comprising aluminum sulphate containing not more than fourteen molecules of water of crystallization, an ingredient capable of reacting therewith in the presence of water,-

a stabilizer and an inert material. p

9. A fire-extinguishing composition com- :prising aluminum sulphate containing not more than fourteen molecules of water of crystallization, an ingredient capable of reacting therewith in the presence of water, a

stabilizer and from 8 to 35% of.an, inert material," p

10. A fire-extinguishing composition comprising aluminum sulphate containing not more than fourteen molecules of water ofcrystallization, an .ingredient capable of reacting therewith in the presence. of water, a stabilizer andan inert material, the sizes of the particles of thereacting ingredients being such as to pass a forty mesh sieve.

11. A fire-extinguishing composition commore than fourteen molecules of water 0 crystallization, an ingredient capable of reacting therewith in the presence of water, a

' stabilizer and from 8 to 35%of an inert prising aluminum sulphate; sodium bicarbonate, a foam stabilizer and an inert materiai to avoid deterioration of the composition 1n storage. o a p v 13. A fire-extinguishing composition comprising aluminum sulphate, sodium bicarbona-te, afoamhstabilizer and from 8 to g 35% of an inert material to avoid deterioration of the composition in storage.

14. A fire-extingulshing compositioncom- I prising aluminum sulphate, sodium' bicarhona'te, a foam stabilizer and an inert mate- I rial' to avoid deterioration of the composition in storage, the size of the particles of aluminum sulphate and sodium carbonate being such as to pass a forty mesh sieve; 15. A fire-extinguishing composition com-v prising aluminum sulphate, sodium bicare onate, a. foam stabilizer and from 8 1:03.57?) of an inert material to avoiddeterioration of the composition in storage, the size of the particles of aluminum sulphate andsodium bicarbonate being such as to pass a forty mesh sieve.

In testimony tures.

FREDERICK L. DUNLA/P. NATHANIEL T. EWER.

whereof We aflix our signa 

